Characteristic analysis of wideband beam monitor with high-frequency pickups

The signal transmission characteristics of a wideband beam monitor (WBM) with feedthrough electrodes are discussed in the frequency region up to 13.5 GHz on the basis of a coupled-mode analysis using an equivalent circuit model with electromagnetically coupled transmission lines. It is demonstrated that in the signal transmission characteristics based on an electromagnetic induction method, electromagnetic couplings for fundamental and higher-order rf waves play an important role depending on the spatial configuration and geometrical structure of the electrodes mounted on the WBM with a cylindrical structure. The physical prospect in the calibration procedure of feedthrough electrodes is improved in terms of the signal transmission characteristics over the frequency region. In this report, the modal analyses and experimental investigations of the signal transmission characteristics in the WBM are described in detail. An alternative method of gain calibration for each electrode is also demonstrated.